Question!

What is a summer sore? And what can I do about it?

Have you heard yourself say this before: “Now THAT wasn’t there yesterday!”. I say this a lot, as I’m often finding scrapes, dings, scratches, cuts, boo boos, and the like on horses that I groom. Most of the time, it’s no big deal. Sometimes, it’s a huge deal with serious consequences if summer sores develop. A summer sore can sometimes take a YEAR to heal, often sidelining your horse from activity.

Summer sores (aka Habronemiasis) happen when worms begin to live in a cut or soft tissue on your horse. Yup, worms. Here are the details if you can take it: There’s a species of horse stomach worm, the Habronema, that pass their larvae in your horse’s manure. Flies then eat the larvae. When the infected flies then land on your horse’s cut, scrape, mucous membrane, eye area, genital area, anal area, lip, etc. The worms then begin to cause a huge inflammatory response within your horse, resulting in a HUGE wound, often within a couple of days.

Summer sores can occur inside the sheath, udders, under the tail, and even around eyes. Sometimes they happen without a cut or initial incident.

Veterinary intervention is critical. Summer sores often resemble other types of horse lesions, from cancers to proud flesh to fungal infections to bacterial infections. Your Veterinarian may need to take a tissue sample for laboratory analysis, which will then determine what types of medications are necessary. If your horse’s lesion is a summer sore, you will also need to give deworming medications, usually in conjunction with antibiotics and anti-inflammatory mediations.

This healing summer sore prevents a bit from being used. You can use a hackamore, bosal, or other bitless bridle so the wound has time to heal.

This summer sore on the inside of the sheath shows how large the sores can be. (This horse is now feeling much better after some great care!)

Because this infection is caused by internal parasites and external parasites, it’s up to you to do prevent these infections. Regular fecal testing and deworming is critical for all horses in the area. No internal parasites, decreased chance of summer sores. But this is hard if you live next to other farms that may not be so current on this. You also need to attack the flies at all stages of their life cycle. Not only will everyone on the farm be happy to have fewer flies, you will reduce the chance of the Habronema worm infecting you horse.

Cover those scrapes and cuts!

You can also create a barrier between cuts and scrapes if it’s appropriate. Wrapping or covering wounds may be beneficial to prevent the flies from depositing the worm larvae. Consult with your Veterinarian about this as soon as you find a new scrape to determine if covering it is best.